#include <iostream>
#include <vector>
using namespace std;

class Test{
public:
	void reverseString(vector<char>& s) {
		int left = 0;
		int right = s.size()-1;
		while(left < right){
			char tmp = s[left];
			s[left] = s[right];
			s[right] = tmp;
			left++;
			right--;
		}
	}
};


int main(){
	
	return 0;
}
